COMPMID-421: Added FP16 support to Softmax.

Change-Id: If48178689e7cdadf1858556438c7292128be5b92
Reviewed-on: http://mpd-gerrit.cambridge.arm.com/80436
Tested-by: Kaizen <jeremy.johnson+kaizengerrit@arm.com>
Reviewed-by: Moritz Pflanzer <moritz.pflanzer@arm.com>
10 files changed